Here is a clear version suitable for both exams and construction sites:4 main types of road rollers + their applicable road structures, easy to understand and memorize.

I. Common Roller Types and Applicable Road Structures

1. Single-Drum Vibratory Roller

• Appearance: Front steel drum (vibratory), rear tires

• Main applications:

• Subgrade earthwork, sand & gravel cushion

• Cement-stabilized crushed stone base

• Not suitable for: Asphalt surface course (easily crushes and shoves material)

• One-sentence summary:Compacts subgrade and base layers; handles all lower road layers.

2. Tandem-Drum Vibratory Roller

• Appearance: Two steel drums (front and rear), can vibrate or use static pressure

• Main applications:

• Asphalt pavement: initial rolling, intermediate rolling (vibratory), final rolling (static)

• Thin-layer repair of cement concrete pavement

• Features: Good smoothness, no asphalt adhesion

• One-sentence summary:Special machine for asphalt pavements, supports both static and vibratory rolling.

3. Pneumatic-Tired Roller

• Appearance: All rubber tires (e.g., 4 front, 5 rear)

• Main applications:

• Asphalt pavement: intermediate rolling, final rolling

• Kneading compaction, void sealing, surface finishing

• Not suitable for: Subgrade, cement-stabilized layers (easily sinks)

• One-sentence summary:Kneading machine for asphalt final rolling, seals and waterproofs while improving gloss.

4. Static Roller (Smooth-Wheeled Static)

• Appearance: Steel drum, no vibration, relies only on dead weight

• Main applications:

• Pavement leveling and finishing

• Stabilization of thin layers and crack-prone structures

• One-sentence summary:Only levels without vibratory compaction; used for finishing and stabilization.

II. Quick Overview Table

III. Easy Memory Formula

• Single-drum: compacts subgrade and base

• Tandem-drum: compacts asphalt through all stages

• Pneumatic-tired: compacts asphalt, kneads and seals voids

• Static: stabilizes and finishes without vibration